1 ThinkPad ACPI Extras Driver
6 Borislav Deianov <borislav@users.sf.net>
7 Henrique de Moraes Holschuh <hmh@hmh.eng.br>
8 http://ibm-acpi.sf.net/
11 This is a Linux driver for the IBM and Lenovo ThinkPad laptops. It
12 supports various features of these laptops which are accessible
13 through the ACPI and ACPI EC framework, but not otherwise fully
14 supported by the generic Linux ACPI drivers.
16 This driver used to be named ibm-acpi until kernel 2.6.21 and release
17 0.13-20070314. It used to be in the drivers/acpi tree, but it was
18 moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel
19 2.6.22, and release 0.14.
25 The features currently supported are the following (see below for
26 detailed description):
29 - Bluetooth enable and disable
30 - video output switching, expansion control
31 - ThinkLight on and off
32 - limited docking and undocking
38 - Experimental: embedded controller register dump
39 - LCD brightness control
41 - Fan control and monitoring: fan speed, fan enable/disable
42 - Experimental: WAN enable and disable
44 A compatibility table by model and feature is maintained on the web
45 site, http://ibm-acpi.sf.net/. I appreciate any success or failure
46 reports, especially if they add to or correct the compatibility table.
47 Please include the following information in your report:
50 - a copy of your DSDT, from /proc/acpi/dsdt
51 - a copy of the output of dmidecode, with serial numbers
53 - which driver features work and which don't
54 - the observed behavior of non-working features
56 Any other comments or patches are also more than welcome.
62 If you are compiling this driver as included in the Linux kernel
63 sources, simply enable the CONFIG_THINKPAD_ACPI option, and optionally
64 enable the CONFIG_THINKPAD_ACPI_BAY option if you want the
65 thinkpad-specific bay functionality.
70 The driver exports two different interfaces to userspace, which can be
71 used to access the features it provides. One is a legacy procfs-based
72 interface, which will be removed at some time in the distant future.
73 The other is a new sysfs-based interface which is not complete yet.
75 The procfs interface creates the /proc/acpi/ibm directory. There is a
76 file under that directory for each feature it supports. The procfs
77 interface is mostly frozen, and will change very little if at all: it
78 will not be extended to add any new functionality in the driver, instead
79 all new functionality will be implemented on the sysfs interface.
81 The sysfs interface tries to blend in the generic Linux sysfs subsystems
82 and classes as much as possible. Since some of these subsystems are not
83 yet ready or stabilized, it is expected that this interface will change,
84 and any and all userspace programs must deal with it.
87 Notes about the sysfs interface:
89 Unlike what was done with the procfs interface, correctness when talking
90 to the sysfs interfaces will be enforced, as will correctness in the
91 thinkpad-acpi's implementation of sysfs interfaces.
93 Also, any bugs in the thinkpad-acpi sysfs driver code or in the
94 thinkpad-acpi's implementation of the sysfs interfaces will be fixed for
95 maximum correctness, even if that means changing an interface in
96 non-compatible ways. As these interfaces mature both in the kernel and
97 in thinkpad-acpi, such changes should become quite rare.
99 Applications interfacing to the thinkpad-acpi sysfs interfaces must
100 follow all sysfs guidelines and correctly process all errors (the sysfs
101 interface makes extensive use of errors). File descriptors and open /
102 close operations to the sysfs inodes must also be properly implemented.
104 Also, as per the sysfs guidelines, if a feature is permanently
105 unavailable (e.g. bluetooth), the driver or device is not to expose
106 attributes dealing with that interface. Applications must do the right
107 thing if an attribute is missing.
109 The version of thinkpad-acpi's sysfs interface is exported by the driver
110 as a driver attribute (see below).
112 Sysfs driver attributes are on the driver's sysfs attribute space,
113 for 2.6.23 this is /sys/bus/platform/drivers/thinkpad_acpi/ and
114 /sys/bus/platform/drivers/thinkpad_hwmon/
116 Sysfs device attributes are on the thinkpad_acpi device sysfs attribute
117 space, for 2.6.23 this is /sys/devices/platform/thinkpad_acpi/.
119 Sysfs device attributes for the sensors and fan are on the
120 thinkpad_hwmon device's sysfs attribute space, but you should locate it
121 looking for a hwmon device with the name attribute of "thinkpad".
126 procfs: /proc/acpi/ibm/driver
127 sysfs driver attribute: version
129 The driver name and version. No commands can be written to this file.
131 Sysfs interface version
132 -----------------------
134 sysfs driver attribute: interface_version
136 Version of the thinkpad-acpi sysfs interface, as an unsigned long
137 (output in hex format: 0xAAAABBCC), where:
138 AAAA - major revision
142 The sysfs interface version changelog for the driver can be found at the
143 end of this document. Changes to the sysfs interface done by the kernel
144 subsystems are not documented here, nor are they tracked by this
147 Changes to the thinkpad-acpi sysfs interface are only considered
148 non-experimental when they are submitted to Linux mainline, at which
149 point the changes in this interface are documented and interface_version
150 may be updated. If you are using any thinkpad-acpi features not yet
151 sent to mainline for merging, you do so on your own risk: these features
152 may disappear, or be implemented in a different and incompatible way by
153 the time they are merged in Linux mainline.
155 Changes that are backwards-compatible by nature (e.g. the addition of
156 attributes that do not change the way the other attributes work) do not
157 always warrant an update of interface_version. Therefore, one must
158 expect that an attribute might not be there, and deal with it properly
159 (an attribute not being there *is* a valid way to make it clear that a
160 feature is not available in sysfs).
165 procfs: /proc/acpi/ibm/hotkey
166 sysfs device attribute: hotkey_*
168 In a ThinkPad, the ACPI HKEY handler is responsible for comunicating
169 some important events and also keyboard hot key presses to the operating
170 system. Enabling the hotkey functionality of thinkpad-acpi signals the
171 firmware that such a driver is present, and modifies how the ThinkPad
172 firmware will behave in many situations.
174 The driver enables the hot key feature automatically when loaded. The
175 feature can later be disabled and enabled back at runtime. The driver
176 will also restore the hot key feature to its previous state and mask
179 When the hotkey feature is enabled and the hot key mask is set (see
180 below), the driver will report HKEY events in the following format:
182 ibm/hotkey HKEY 00000080 0000xxxx
184 Some of these events refer to hot key presses, but not all.
186 The driver will generate events over the input layer for hot keys and
187 radio switches, and over the ACPI netlink layer for other events. The
188 input layer support accepts the standard IOCTLs to remap the keycodes
189 assigned to each hot key.
191 The hot key bit mask allows some control over which hot keys generate
192 events. If a key is "masked" (bit set to 0 in the mask), the firmware
193 will handle it. If it is "unmasked", it signals the firmware that
194 thinkpad-acpi would prefer to handle it, if the firmware would be so
195 kind to allow it (and it often doesn't!).
197 Not all bits in the mask can be modified. Not all bits that can be
198 modified do anything. Not all hot keys can be individually controlled
199 by the mask. Some models do not support the mask at all, and in those
200 models, hot keys cannot be controlled individually. The behaviour of
201 the mask is, therefore, higly dependent on the ThinkPad model.
203 Note that unmasking some keys prevents their default behavior. For
204 example, if Fn+F5 is unmasked, that key will no longer enable/disable
207 Note also that not all Fn key combinations are supported through ACPI.
208 For example, on the X40, the brightness, volume and "Access IBM" buttons
209 do not generate ACPI events even with this driver. They *can* be used
210 through the "ThinkPad Buttons" utility, see http://www.nongnu.org/tpb/
214 The following commands can be written to the /proc/acpi/ibm/hotkey file:
216 echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature
217 echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature
218 echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys
219 echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys
220 ... any other 8-hex-digit mask ...
221 echo reset > /proc/acpi/ibm/hotkey -- restore the original mask
226 Returns the status of the hot keys feature when
227 thinkpad-acpi was loaded. Upon module unload, the hot
228 key feature status will be restored to this value.
230 0: hot keys were disabled
231 1: hot keys were enabled (unusual)
234 Returns the hot keys mask when thinkpad-acpi was loaded.
235 Upon module unload, the hot keys mask will be restored
239 Enables/disables the hot keys feature, and reports
240 current status of the hot keys feature.
242 0: disables the hot keys feature / feature disabled
243 1: enables the hot keys feature / feature enabled
246 bit mask to enable driver-handling (and depending on
247 the firmware, ACPI event generation) for each hot key
248 (see above). Returns the current status of the hot keys
249 mask, and allows one to modify it.
252 bit mask that should enable event reporting for all
253 supported hot keys, when echoed to hotkey_mask above.
254 Unless you know which events need to be handled
255 passively (because the firmware *will* handle them
256 anyway), do *not* use hotkey_all_mask. Use
257 hotkey_recommended_mask, instead. You have been warned.
259 hotkey_recommended_mask:
260 bit mask that should enable event reporting for all
261 supported hot keys, except those which are always
262 handled by the firmware anyway. Echo it to
263 hotkey_mask above, to use.
266 bit mask that selects which hot keys will the driver
267 poll the CMOS NVRAM for. This is auto-detected by the
268 driver based on the capabilities reported by the ACPI
269 firmware, but it can be overridden at runtime for
272 Hot keys whose bits are set in hotkey_source_mask (and
273 also on hotkey_mask) are polled for in NVRAM. Only a
274 few hot keys are available through CMOS NVRAM polling.
277 frequency in Hz for hot key polling. It must be between
278 0 and 25 Hz. Polling is only carried out when strictly
281 Setting hotkey_poll_freq to zero disables polling, and
282 will cause hot key presses that require NVRAM polling
283 to never be reported.
285 Setting hotkey_poll_freq too low will cause repeated
286 pressings of the same hot key to be misreported as a
287 single key press, or to not even be detected at all.
290 if the ThinkPad has a hardware radio switch, this
291 attribute will read 0 if the switch is in the "radios
292 disabled" postition, and 1 if the switch is in the
293 "radios enabled" position.
296 Returns the state of the procfs ACPI event report mode
297 filter for hot keys. If it is set to 1 (the default),
298 all hot key presses are reported both through the input
299 layer and also as ACPI events through procfs (but not
300 through netlink). If it is set to 2, hot key presses
301 are reported only through the input layer.
303 This attribute is read-only in kernels 2.6.23 or later,
304 and read-write on earlier kernels.
306 May return -EPERM (write access locked out by module
307 parameter) or -EACCES (read-only).
311 A Hot key is mapped to a single input layer EV_KEY event, possibly
312 followed by an EV_MSC MSC_SCAN event that shall contain that key's scan
313 code. An EV_SYN event will always be generated to mark the end of the
316 Do not use the EV_MSC MSC_SCAN events to process keys. They are to be
317 used as a helper to remap keys, only. They are particularly useful when
318 remapping KEY_UNKNOWN keys.
320 The events are available in an input device, with the following id:
323 vendor: 0x1014 (PCI_VENDOR_ID_IBM) or
324 0x17aa (PCI_VENDOR_ID_LENOVO)
325 product: 0x5054 ("TP")
328 The version will have its LSB incremented if the keymap changes in a
329 backwards-compatible way. The MSB shall always be 0x41 for this input
330 device. If the MSB is not 0x41, do not use the device as described in
331 this section, as it is either something else (e.g. another input device
332 exported by a thinkpad driver, such as HDAPS) or its functionality has
333 been changed in a non-backwards compatible way.
335 Adding other event types for other functionalities shall be considered a
336 backwards-compatible change for this input device.
338 Thinkpad-acpi Hot Key event map (version 0x4101):
344 0x1002 0x01 FN+F2 IBM: battery (rare)
347 0x1003 0x02 FN+F3 Many IBM models always report
348 this hot key, even with hot keys
349 disabled or with Fn+F3 masked
354 0x1004 0x03 FN+F4 Sleep button (ACPI sleep button
355 semanthics, i.e. sleep-to-RAM).
356 It is always generate some kind
357 of event, either the hot key
358 event or a ACPI sleep button
359 event. The firmware may
360 refuse to generate further FN+F4
361 key presses until a S3 or S4 ACPI
362 sleep cycle is performed or some
365 0x1005 0x04 FN+F5 Radio. Enables/disables
366 the internal BlueTooth hardware
367 and W-WAN card if left in control
368 of the firmware. Does not affect
370 Should be used to turn on/off all
371 radios (bluetooth+W-WAN+WLAN),
376 0x1007 0x06 FN+F7 Video output cycle.
377 Do you feel lucky today?
379 0x1008 0x07 FN+F8 IBM: toggle screen expand
380 Lenovo: configure ultranav
386 0x100C 0x0B FN+F12 Sleep to disk. You are always
387 supposed to handle it yourself,
388 either through the ACPI event,
389 or through a hotkey event.
390 The firmware may refuse to
391 generate further FN+F4 key
392 press events until a S3 or S4
393 ACPI sleep cycle is performed,
396 0x100D 0x0C FN+BACKSPACE -
397 0x100E 0x0D FN+INSERT -
398 0x100F 0x0E FN+DELETE -
400 0x1010 0x0F FN+HOME Brightness up. This key is
401 always handled by the firmware
402 in IBM ThinkPads, even when
403 unmasked. Just leave it alone.
404 For Lenovo ThinkPads with a new
405 BIOS, it has to be handled either
406 by the ACPI OSI, or by userspace.
407 0x1011 0x10 FN+END Brightness down. See brightness
410 0x1012 0x11 FN+PGUP Thinklight toggle. This key is
411 always handled by the firmware,
414 0x1013 0x12 FN+PGDOWN -
416 0x1014 0x13 FN+SPACE Zoom key
418 0x1015 0x14 VOLUME UP Internal mixer volume up. This
419 key is always handled by the
420 firmware, even when unmasked.
421 NOTE: Lenovo seems to be changing
423 0x1016 0x15 VOLUME DOWN Internal mixer volume up. This
424 key is always handled by the
425 firmware, even when unmasked.
426 NOTE: Lenovo seems to be changing
428 0x1017 0x16 MUTE Mute internal mixer. This
429 key is always handled by the
430 firmware, even when unmasked.
432 0x1018 0x17 THINKPAD Thinkpad/Access IBM/Lenovo key
438 The ThinkPad firmware does not allow one to differentiate when most hot
439 keys are pressed or released (either that, or we don't know how to, yet).
440 For these keys, the driver generates a set of events for a key press and
441 immediately issues the same set of events for a key release. It is
442 unknown by the driver if the ThinkPad firmware triggered these events on
443 hot key press or release, but the firmware will do it for either one, not
446 If a key is mapped to KEY_RESERVED, it generates no input events at all.
447 If a key is mapped to KEY_UNKNOWN, it generates an input event that
448 includes an scan code. If a key is mapped to anything else, it will
449 generate input device EV_KEY events.
451 Non hot-key ACPI HKEY event map:
454 0x7000 Radio Switch may have changed state
456 The above events are not propagated by the driver, except for legacy
457 compatibility purposes when hotkey_report_mode is set to 1.
461 ibm-acpi and thinkpad-acpi 0.15 (mainline kernels before 2.6.23) never
462 supported the input layer, and sent events over the procfs ACPI event
465 To avoid sending duplicate events over the input layer and the ACPI
466 event interface, thinkpad-acpi 0.16 implements a module parameter
467 (hotkey_report_mode), and also a sysfs device attribute with the same
470 Make no mistake here: userspace is expected to switch to using the input
471 layer interface of thinkpad-acpi, together with the ACPI netlink event
472 interface in kernels 2.6.23 and later, or with the ACPI procfs event
473 interface in kernels 2.6.22 and earlier.
475 If no hotkey_report_mode module parameter is specified (or it is set to
476 zero), the driver defaults to mode 1 (see below), and on kernels 2.6.22
477 and earlier, also allows one to change the hotkey_report_mode through
478 sysfs. In kernels 2.6.23 and later, where the netlink ACPI event
479 interface is available, hotkey_report_mode cannot be changed through
480 sysfs (it is read-only).
482 If the hotkey_report_mode module parameter is set to 1 or 2, it cannot
483 be changed later through sysfs (any writes will return -EPERM to signal
484 that hotkey_report_mode was locked. On 2.6.23 and later, where
485 hotkey_report_mode cannot be changed at all, writes will return -EACES).
487 hotkey_report_mode set to 1 makes the driver export through the procfs
488 ACPI event interface all hot key presses (which are *also* sent to the
489 input layer). This is a legacy compatibility behaviour, and it is also
490 the default mode of operation for the driver.
492 hotkey_report_mode set to 2 makes the driver filter out the hot key
493 presses from the procfs ACPI event interface, so these events will only
494 be sent through the input layer. Userspace that has been updated to use
495 the thinkpad-acpi input layer interface should set hotkey_report_mode to
498 Hot key press events are never sent to the ACPI netlink event interface.
499 Really up-to-date userspace under kernel 2.6.23 and later is to use the
500 netlink interface and the input layer interface, and don't bother at all
501 with hotkey_report_mode.
507 procfs: /proc/acpi/ibm/bluetooth
508 sysfs device attribute: bluetooth_enable
510 This feature shows the presence and current state of a ThinkPad
511 Bluetooth device in the internal ThinkPad CDC slot.
515 If Bluetooth is installed, the following commands can be used:
517 echo enable > /proc/acpi/ibm/bluetooth
518 echo disable > /proc/acpi/ibm/bluetooth
522 If the Bluetooth CDC card is installed, it can be enabled /
523 disabled through the "bluetooth_enable" thinkpad-acpi device
524 attribute, and its current status can also be queried.
527 0: disables Bluetooth / Bluetooth is disabled
528 1: enables Bluetooth / Bluetooth is enabled.
530 Note: this interface will be probably be superseeded by the
531 generic rfkill class, so it is NOT to be considered stable yet.
533 Video output control -- /proc/acpi/ibm/video
534 --------------------------------------------
536 This feature allows control over the devices used for video output -
537 LCD, CRT or DVI (if available). The following commands are available:
539 echo lcd_enable > /proc/acpi/ibm/video
540 echo lcd_disable > /proc/acpi/ibm/video
541 echo crt_enable > /proc/acpi/ibm/video
542 echo crt_disable > /proc/acpi/ibm/video
543 echo dvi_enable > /proc/acpi/ibm/video
544 echo dvi_disable > /proc/acpi/ibm/video
545 echo auto_enable > /proc/acpi/ibm/video
546 echo auto_disable > /proc/acpi/ibm/video
547 echo expand_toggle > /proc/acpi/ibm/video
548 echo video_switch > /proc/acpi/ibm/video
550 Each video output device can be enabled or disabled individually.
551 Reading /proc/acpi/ibm/video shows the status of each device.
553 Automatic video switching can be enabled or disabled. When automatic
554 video switching is enabled, certain events (e.g. opening the lid,
555 docking or undocking) cause the video output device to change
556 automatically. While this can be useful, it also causes flickering
557 and, on the X40, video corruption. By disabling automatic switching,
558 the flickering or video corruption can be avoided.
560 The video_switch command cycles through the available video outputs
561 (it simulates the behavior of Fn-F7).
563 Video expansion can be toggled through this feature. This controls
564 whether the display is expanded to fill the entire LCD screen when a
565 mode with less than full resolution is used. Note that the current
566 video expansion status cannot be determined through this feature.
568 Note that on many models (particularly those using Radeon graphics
569 chips) the X driver configures the video card in a way which prevents
570 Fn-F7 from working. This also disables the video output switching
571 features of this driver, as it uses the same ACPI methods as
572 Fn-F7. Video switching on the console should still work.
574 UPDATE: There's now a patch for the X.org Radeon driver which
575 addresses this issue. Some people are reporting success with the patch
576 while others are still having problems. For more information:
578 https://bugs.freedesktop.org/show_bug.cgi?id=2000
580 ThinkLight control -- /proc/acpi/ibm/light
581 ------------------------------------------
583 The current status of the ThinkLight can be found in this file. A few
584 models which do not make the status available will show it as
585 "unknown". The available commands are:
587 echo on > /proc/acpi/ibm/light
588 echo off > /proc/acpi/ibm/light
590 Docking / undocking -- /proc/acpi/ibm/dock
591 ------------------------------------------
593 Docking and undocking (e.g. with the X4 UltraBase) requires some
594 actions to be taken by the operating system to safely make or break
595 the electrical connections with the dock.
597 The docking feature of this driver generates the following ACPI events:
599 ibm/dock GDCK 00000003 00000001 -- eject request
600 ibm/dock GDCK 00000003 00000002 -- undocked
601 ibm/dock GDCK 00000000 00000003 -- docked
603 NOTE: These events will only be generated if the laptop was docked
604 when originally booted. This is due to the current lack of support for
605 hot plugging of devices in the Linux ACPI framework. If the laptop was
606 booted while not in the dock, the following message is shown in the
609 Mar 17 01:42:34 aero kernel: thinkpad_acpi: dock device not present
611 In this case, no dock-related events are generated but the dock and
612 undock commands described below still work. They can be executed
613 manually or triggered by Fn key combinations (see the example acpid
614 configuration files included in the driver tarball package available
617 When the eject request button on the dock is pressed, the first event
618 above is generated. The handler for this event should issue the
621 echo undock > /proc/acpi/ibm/dock
623 After the LED on the dock goes off, it is safe to eject the laptop.
624 Note: if you pressed this key by mistake, go ahead and eject the
625 laptop, then dock it back in. Otherwise, the dock may not function as
628 When the laptop is docked, the third event above is generated. The
629 handler for this event should issue the following command to fully
632 echo dock > /proc/acpi/ibm/dock
634 The contents of the /proc/acpi/ibm/dock file shows the current status
635 of the dock, as provided by the ACPI framework.
637 The docking support in this driver does not take care of enabling or
638 disabling any other devices you may have attached to the dock. For
639 example, a CD drive plugged into the UltraBase needs to be disabled or
640 enabled separately. See the provided example acpid configuration files
641 for how this can be accomplished.
643 There is no support yet for PCI devices that may be attached to a
644 docking station, e.g. in the ThinkPad Dock II. The driver currently
645 does not recognize, enable or disable such devices. This means that
646 the only docking stations currently supported are the X-series
647 UltraBase docks and "dumb" port replicators like the Mini Dock (the
648 latter don't need any ACPI support, actually).
650 UltraBay eject -- /proc/acpi/ibm/bay
651 ------------------------------------
653 Inserting or ejecting an UltraBay device requires some actions to be
654 taken by the operating system to safely make or break the electrical
655 connections with the device.
657 This feature generates the following ACPI events:
659 ibm/bay MSTR 00000003 00000000 -- eject request
660 ibm/bay MSTR 00000001 00000000 -- eject lever inserted
662 NOTE: These events will only be generated if the UltraBay was present
663 when the laptop was originally booted (on the X series, the UltraBay
664 is in the dock, so it may not be present if the laptop was undocked).
665 This is due to the current lack of support for hot plugging of devices
666 in the Linux ACPI framework. If the laptop was booted without the
667 UltraBay, the following message is shown in the logs:
669 Mar 17 01:42:34 aero kernel: thinkpad_acpi: bay device not present
671 In this case, no bay-related events are generated but the eject
672 command described below still works. It can be executed manually or
673 triggered by a hot key combination.
675 Sliding the eject lever generates the first event shown above. The
676 handler for this event should take whatever actions are necessary to
677 shut down the device in the UltraBay (e.g. call idectl), then issue
678 the following command:
680 echo eject > /proc/acpi/ibm/bay
682 After the LED on the UltraBay goes off, it is safe to pull out the
685 When the eject lever is inserted, the second event above is
686 generated. The handler for this event should take whatever actions are
687 necessary to enable the UltraBay device (e.g. call idectl).
689 The contents of the /proc/acpi/ibm/bay file shows the current status
690 of the UltraBay, as provided by the ACPI framework.
692 EXPERIMENTAL warm eject support on the 600e/x, A22p and A3x (To use
693 this feature, you need to supply the experimental=1 parameter when
696 These models do not have a button near the UltraBay device to request
697 a hot eject but rather require the laptop to be put to sleep
698 (suspend-to-ram) before the bay device is ejected or inserted).
699 The sequence of steps to eject the device is as follows:
701 echo eject > /proc/acpi/ibm/bay
702 put the ThinkPad to sleep
705 cat /proc/acpi/ibm/bay should show that the drive was removed
707 On the A3x, both the UltraBay 2000 and UltraBay Plus devices are
708 supported. Use "eject2" instead of "eject" for the second bay.
710 Note: the UltraBay eject support on the 600e/x, A22p and A3x is
711 EXPERIMENTAL and may not work as expected. USE WITH CAUTION!
716 procfs: /proc/acpi/ibm/cmos
717 sysfs device attribute: cmos_command
719 This feature is mostly used internally by the ACPI firmware to keep the legacy
720 CMOS NVRAM bits in sync with the current machine state, and to record this
721 state so that the ThinkPad will retain such settings across reboots.
723 Some of these commands actually perform actions in some ThinkPad models, but
724 this is expected to disappear more and more in newer models. As an example, in
725 a T43 and in a X40, commands 12 and 13 still control the ThinkLight state for
726 real, but commands 0 to 2 don't control the mixer anymore (they have been
727 phased out) and just update the NVRAM.
729 The range of valid cmos command numbers is 0 to 21, but not all have an
730 effect and the behavior varies from model to model. Here is the behavior
731 on the X40 (tpb is the ThinkPad Buttons utility):
733 0 - Related to "Volume down" key press
734 1 - Related to "Volume up" key press
735 2 - Related to "Mute on" key press
736 3 - Related to "Access IBM" key press
737 4 - Related to "LCD brightness up" key pess
738 5 - Related to "LCD brightness down" key press
739 11 - Related to "toggle screen expansion" key press/function
740 12 - Related to "ThinkLight on"
741 13 - Related to "ThinkLight off"
742 14 - Related to "ThinkLight" key press (toggle thinklight)
744 The cmos command interface is prone to firmware split-brain problems, as
745 in newer ThinkPads it is just a compatibility layer. Do not use it, it is
746 exported just as a debug tool.
748 LED control -- /proc/acpi/ibm/led
749 ---------------------------------
751 Some of the LED indicators can be controlled through this feature. The
752 available commands are:
754 echo '<led number> on' >/proc/acpi/ibm/led
755 echo '<led number> off' >/proc/acpi/ibm/led
756 echo '<led number> blink' >/proc/acpi/ibm/led
758 The <led number> range is 0 to 7. The set of LEDs that can be
759 controlled varies from model to model. Here is the mapping on the X40:
768 All of the above can be turned on and off and can be made to blink.
770 ACPI sounds -- /proc/acpi/ibm/beep
771 ----------------------------------
773 The BEEP method is used internally by the ACPI firmware to provide
774 audible alerts in various situations. This feature allows the same
775 sounds to be triggered manually.
777 The commands are non-negative integer numbers:
779 echo <number> >/proc/acpi/ibm/beep
781 The valid <number> range is 0 to 17. Not all numbers trigger sounds
782 and the sounds vary from model to model. Here is the behavior on the
785 0 - stop a sound in progress (but use 17 to stop 16)
786 2 - two beeps, pause, third beep ("low battery")
788 4 - high, followed by low-pitched beep ("unable")
790 6 - very high, followed by high-pitched beep ("AC/DC")
791 7 - high-pitched beep
792 9 - three short beeps
794 12 - low-pitched beep
795 15 - three high-pitched beeps repeating constantly, stop with 0
796 16 - one medium-pitched beep repeating constantly, stop with 17
802 procfs: /proc/acpi/ibm/thermal
803 sysfs device attributes: (hwmon "thinkpad") temp*_input
805 Most ThinkPads include six or more separate temperature sensors but only
806 expose the CPU temperature through the standard ACPI methods. This
807 feature shows readings from up to eight different sensors on older
808 ThinkPads, and up to sixteen different sensors on newer ThinkPads.
810 For example, on the X40, a typical output may be:
811 temperatures: 42 42 45 41 36 -128 33 -128
813 On the T43/p, a typical output may be:
814 temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
816 The mapping of thermal sensors to physical locations varies depending on
817 system-board model (and thus, on ThinkPad model).
819 http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
820 tries to track down these locations for various models.
822 Most (newer?) models seem to follow this pattern:
825 2: (depends on model)
826 3: (depends on model)
828 5: Main battery: main sensor
829 6: Bay battery: main sensor
830 7: Main battery: secondary sensor
831 8: Bay battery: secondary sensor
832 9-15: (depends on model)
834 For the R51 (source: Thomas Gruber):
838 For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
839 http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_T43.2C_T43p
840 2: System board, left side (near PCMCIA slot), reported as HDAPS temp
842 9: MCH (northbridge) to DRAM Bus
843 10: Clock-generator, mini-pci card and ICH (southbridge), under Mini-PCI
845 11: Power regulator, underside of system board, below F2 key
847 The A31 has a very atypical layout for the thermal sensors
848 (source: Milos Popovic, http://thinkwiki.org/wiki/Thermal_Sensors#ThinkPad_A31)
850 2: Main Battery: main sensor
852 4: Bay Battery: main sensor
855 7: Main Battery: secondary sensor
856 8: Bay Battery: secondary sensor
860 Readings from sensors that are not available return -128.
861 No commands can be written to this file.
864 Sensors that are not available return the ENXIO error. This
865 status may change at runtime, as there are hotplug thermal
866 sensors, like those inside the batteries and docks.
868 thinkpad-acpi thermal sensors are reported through the hwmon
869 subsystem, and follow all of the hwmon guidelines at
873 EXPERIMENTAL: Embedded controller register dump -- /proc/acpi/ibm/ecdump
874 ------------------------------------------------------------------------
876 This feature is marked EXPERIMENTAL because the implementation
877 directly accesses hardware registers and may not work as expected. USE
878 WITH CAUTION! To use this feature, you need to supply the
879 experimental=1 parameter when loading the module.
881 This feature dumps the values of 256 embedded controller
882 registers. Values which have changed since the last time the registers
883 were dumped are marked with a star:
885 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
886 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
887 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
888 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
889 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
890 EC 0x30: 01 07 1a 00 30 04 00 00 *85 00 00 10 00 50 00 00
891 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
892 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 *bc *02 *bc
893 EC 0x60: *02 *bc *02 00 00 00 00 00 00 00 00 00 00 00 00 00
894 EC 0x70: 00 00 00 00 00 12 30 40 *24 *26 *2c *27 *20 80 *1f 80
895 EC 0x80: 00 00 00 06 *37 *0e 03 00 00 00 0e 07 00 00 00 00
896 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
897 EC 0xa0: *ff 09 ff 09 ff ff *64 00 *00 *00 *a2 41 *ff *ff *e0 00
898 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
899 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
900 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
901 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
902 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
904 This feature can be used to determine the register holding the fan
905 speed on some models. To do that, do the following:
907 - make sure the battery is fully charged
908 - make sure the fan is running
909 - run 'cat /proc/acpi/ibm/ecdump' several times, once per second or so
911 The first step makes sure various charging-related values don't
912 vary. The second ensures that the fan-related values do vary, since
913 the fan speed fluctuates a bit. The third will (hopefully) mark the
914 fan register with a star:
916 [root@x40 ibm-acpi]# cat /proc/acpi/ibm/ecdump
917 EC +00 +01 +02 +03 +04 +05 +06 +07 +08 +09 +0a +0b +0c +0d +0e +0f
918 EC 0x00: a7 47 87 01 fe 96 00 08 01 00 cb 00 00 00 40 00
919 EC 0x10: 00 00 ff ff f4 3c 87 09 01 ff 42 01 ff ff 0d 00
920 EC 0x20: 00 00 00 00 00 00 00 00 00 00 00 03 43 00 00 80
921 EC 0x30: 01 07 1a 00 30 04 00 00 85 00 00 10 00 50 00 00
922 EC 0x40: 00 00 00 00 00 00 14 01 00 04 00 00 00 00 00 00
923 EC 0x50: 00 c0 02 0d 00 01 01 02 02 03 03 03 03 bc 02 bc
924 EC 0x60: 02 bc 02 00 00 00 00 00 00 00 00 00 00 00 00 00
925 EC 0x70: 00 00 00 00 00 12 30 40 24 27 2c 27 21 80 1f 80
926 EC 0x80: 00 00 00 06 *be 0d 03 00 00 00 0e 07 00 00 00 00
927 EC 0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
928 EC 0xa0: ff 09 ff 09 ff ff 64 00 00 00 a2 41 ff ff e0 00
929 EC 0xb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
930 EC 0xc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
931 EC 0xd0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
932 EC 0xe0: 00 00 00 00 00 00 00 00 11 20 49 04 24 06 55 03
933 EC 0xf0: 31 55 48 54 35 38 57 57 08 2f 45 73 07 65 6c 1a
935 Another set of values that varies often is the temperature
936 readings. Since temperatures don't change vary fast, you can take
937 several quick dumps to eliminate them.
939 You can use a similar method to figure out the meaning of other
940 embedded controller registers - e.g. make sure nothing else changes
941 except the charging or discharging battery to determine which
942 registers contain the current battery capacity, etc. If you experiment
943 with this, do send me your results (including some complete dumps with
944 a description of the conditions when they were taken.)
946 LCD brightness control
947 ----------------------
949 procfs: /proc/acpi/ibm/brightness
950 sysfs backlight device "thinkpad_screen"
952 This feature allows software control of the LCD brightness on ThinkPad
953 models which don't have a hardware brightness slider.
955 It has some limitations: the LCD backlight cannot be actually turned on or
956 off by this interface, and in many ThinkPad models, the "dim while on
957 battery" functionality will be enabled by the BIOS when this interface is
958 used, and cannot be controlled.
960 On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control
961 has eight levels, ranging from 0 to 7. Some of the levels may not be
962 distinct. Later Lenovo models that implement the ACPI v3.0a brightness
963 control methods have 16 levels, ranging from 0 to 15.
965 There are two interfaces to the firmware for brightness control, EC and
966 CMOS. To select which one should be used, use the brightness_mode module
967 parameter: brightness_mode=1 selects EC mode, brightness_mode=2 selects
968 CMOS mode, brightness_mode=3 selects both EC and CMOS. The driver tries
969 to autodetect which interface to use.
973 The available commands are:
975 echo up >/proc/acpi/ibm/brightness
976 echo down >/proc/acpi/ibm/brightness
977 echo 'level <level>' >/proc/acpi/ibm/brightness
981 The interface is implemented through the backlight sysfs class, which is
982 poorly documented at this time.
984 Locate the thinkpad_screen device under /sys/class/backlight, and inside
985 it there will be the following attributes:
988 Reads the maximum brightness the hardware can be set to.
989 The minimum is always zero.
992 Reads what brightness the screen is set to at this instant.
995 Writes request the driver to change brightness to the
996 given value. Reads will tell you what brightness the
997 driver is trying to set the display to when "power" is set
998 to zero and the display has not been dimmed by a kernel
999 power management event.
1002 power management mode, where 0 is "display on", and 1 to 3
1003 will dim the display backlight to brightness level 0
1004 because thinkpad-acpi cannot really turn the backlight
1005 off. Kernel power management events can temporarily
1006 increase the current power management level, i.e. they can
1010 Volume control -- /proc/acpi/ibm/volume
1011 ---------------------------------------
1013 This feature allows volume control on ThinkPad models which don't have
1014 a hardware volume knob. The available commands are:
1016 echo up >/proc/acpi/ibm/volume
1017 echo down >/proc/acpi/ibm/volume
1018 echo mute >/proc/acpi/ibm/volume
1019 echo 'level <level>' >/proc/acpi/ibm/volume
1021 The <level> number range is 0 to 15 although not all of them may be
1022 distinct. The unmute the volume after the mute command, use either the
1023 up or down command (the level command will not unmute the volume).
1024 The current volume level and mute state is shown in the file.
1026 Fan control and monitoring: fan speed, fan enable/disable
1027 ---------------------------------------------------------
1029 procfs: /proc/acpi/ibm/fan
1030 sysfs device attributes: (hwmon "thinkpad") fan1_input, pwm1,
1032 sysfs hwmon driver attributes: fan_watchdog
1034 NOTE NOTE NOTE: fan control operations are disabled by default for
1035 safety reasons. To enable them, the module parameter "fan_control=1"
1036 must be given to thinkpad-acpi.
1038 This feature attempts to show the current fan speed, control mode and
1039 other fan data that might be available. The speed is read directly
1040 from the hardware registers of the embedded controller. This is known
1041 to work on later R, T, X and Z series ThinkPads but may show a bogus
1042 value on other models.
1046 Most ThinkPad fans work in "levels" at the firmware interface. Level 0
1047 stops the fan. The higher the level, the higher the fan speed, although
1048 adjacent levels often map to the same fan speed. 7 is the highest
1049 level, where the fan reaches the maximum recommended speed.
1051 Level "auto" means the EC changes the fan level according to some
1052 internal algorithm, usually based on readings from the thermal sensors.
1054 There is also a "full-speed" level, also known as "disengaged" level.
1055 In this level, the EC disables the speed-locked closed-loop fan control,
1056 and drives the fan as fast as it can go, which might exceed hardware
1057 limits, so use this level with caution.
1059 The fan usually ramps up or down slowly from one speed to another, and
1060 it is normal for the EC to take several seconds to react to fan
1061 commands. The full-speed level may take up to two minutes to ramp up to
1062 maximum speed, and in some ThinkPads, the tachometer readings go stale
1063 while the EC is transitioning to the full-speed level.
1065 WARNING WARNING WARNING: do not leave the fan disabled unless you are
1066 monitoring all of the temperature sensor readings and you are ready to
1067 enable it if necessary to avoid overheating.
1069 An enabled fan in level "auto" may stop spinning if the EC decides the
1070 ThinkPad is cool enough and doesn't need the extra airflow. This is
1071 normal, and the EC will spin the fan up if the varios thermal readings
1074 On the X40, this seems to depend on the CPU and HDD temperatures.
1075 Specifically, the fan is turned on when either the CPU temperature
1076 climbs to 56 degrees or the HDD temperature climbs to 46 degrees. The
1077 fan is turned off when the CPU temperature drops to 49 degrees and the
1078 HDD temperature drops to 41 degrees. These thresholds cannot
1079 currently be controlled.
1081 The ThinkPad's ACPI DSDT code will reprogram the fan on its own when
1082 certain conditions are met. It will override any fan programming done
1083 through thinkpad-acpi.
1085 The thinkpad-acpi kernel driver can be programmed to revert the fan
1086 level to a safe setting if userspace does not issue one of the procfs
1087 fan commands: "enable", "disable", "level" or "watchdog", or if there
1088 are no writes to pwm1_enable (or to pwm1 *if and only if* pwm1_enable is
1089 set to 1, manual mode) within a configurable amount of time of up to
1090 120 seconds. This functionality is called fan safety watchdog.
1092 Note that the watchdog timer stops after it enables the fan. It will be
1093 rearmed again automatically (using the same interval) when one of the
1094 above mentioned fan commands is received. The fan watchdog is,
1095 therefore, not suitable to protect against fan mode changes made through
1096 means other than the "enable", "disable", and "level" procfs fan
1097 commands, or the hwmon fan control sysfs interface.
1101 The fan may be enabled or disabled with the following commands:
1103 echo enable >/proc/acpi/ibm/fan
1104 echo disable >/proc/acpi/ibm/fan
1106 Placing a fan on level 0 is the same as disabling it. Enabling a fan
1107 will try to place it in a safe level if it is too slow or disabled.
1109 The fan level can be controlled with the command:
1111 echo 'level <level>' > /proc/acpi/ibm/fan
1113 Where <level> is an integer from 0 to 7, or one of the words "auto" or
1114 "full-speed" (without the quotes). Not all ThinkPads support the "auto"
1115 and "full-speed" levels. The driver accepts "disengaged" as an alias for
1116 "full-speed", and reports it as "disengaged" for backwards
1119 On the X31 and X40 (and ONLY on those models), the fan speed can be
1120 controlled to a certain degree. Once the fan is running, it can be
1121 forced to run faster or slower with the following command:
1123 echo 'speed <speed>' > /proc/acpi/ibm/fan
1125 The sustainable range of fan speeds on the X40 appears to be from about
1126 3700 to about 7350. Values outside this range either do not have any
1127 effect or the fan speed eventually settles somewhere in that range. The
1128 fan cannot be stopped or started with this command. This functionality
1129 is incomplete, and not available through the sysfs interface.
1131 To program the safety watchdog, use the "watchdog" command.
1133 echo 'watchdog <interval in seconds>' > /proc/acpi/ibm/fan
1135 If you want to disable the watchdog, use 0 as the interval.
1139 The sysfs interface follows the hwmon subsystem guidelines for the most
1140 part, and the exception is the fan safety watchdog.
1142 Writes to any of the sysfs attributes may return the EINVAL error if
1143 that operation is not supported in a given ThinkPad or if the parameter
1144 is out-of-bounds, and EPERM if it is forbidden. They may also return
1145 EINTR (interrupted system call), and EIO (I/O error while trying to talk
1148 Features not yet implemented by the driver return ENOSYS.
1150 hwmon device attribute pwm1_enable:
1151 0: PWM offline (fan is set to full-speed mode)
1152 1: Manual PWM control (use pwm1 to set fan level)
1153 2: Hardware PWM control (EC "auto" mode)
1154 3: reserved (Software PWM control, not implemented yet)
1156 Modes 0 and 2 are not supported by all ThinkPads, and the
1157 driver is not always able to detect this. If it does know a
1158 mode is unsupported, it will return -EINVAL.
1160 hwmon device attribute pwm1:
1161 Fan level, scaled from the firmware values of 0-7 to the hwmon
1162 scale of 0-255. 0 means fan stopped, 255 means highest normal
1165 This attribute only commands the fan if pmw1_enable is set to 1
1166 (manual PWM control).
1168 hwmon device attribute fan1_input:
1169 Fan tachometer reading, in RPM. May go stale on certain
1170 ThinkPads while the EC transitions the PWM to offline mode,
1171 which can take up to two minutes. May return rubbish on older
1174 hwmon driver attribute fan_watchdog:
1175 Fan safety watchdog timer interval, in seconds. Minimum is
1176 1 second, maximum is 120 seconds. 0 disables the watchdog.
1178 To stop the fan: set pwm1 to zero, and pwm1_enable to 1.
1180 To start the fan in a safe mode: set pwm1_enable to 2. If that fails
1181 with EINVAL, try to set pwm1_enable to 1 and pwm1 to at least 128 (255
1182 would be the safest choice, though).
1188 procfs: /proc/acpi/ibm/wan
1189 sysfs device attribute: wwan_enable
1191 This feature is marked EXPERIMENTAL because the implementation
1192 directly accesses hardware registers and may not work as expected. USE
1193 WITH CAUTION! To use this feature, you need to supply the
1194 experimental=1 parameter when loading the module.
1196 This feature shows the presence and current state of a W-WAN (Sierra
1197 Wireless EV-DO) device.
1199 It was tested on a Lenovo Thinkpad X60. It should probably work on other
1200 Thinkpad models which come with this module installed.
1204 If the W-WAN card is installed, the following commands can be used:
1206 echo enable > /proc/acpi/ibm/wan
1207 echo disable > /proc/acpi/ibm/wan
1211 If the W-WAN card is installed, it can be enabled /
1212 disabled through the "wwan_enable" thinkpad-acpi device
1213 attribute, and its current status can also be queried.
1216 0: disables WWAN card / WWAN card is disabled
1217 1: enables WWAN card / WWAN card is enabled.
1219 Note: this interface will be probably be superseeded by the
1220 generic rfkill class, so it is NOT to be considered stable yet.
1222 Multiple Commands, Module Parameters
1223 ------------------------------------
1225 Multiple commands can be written to the proc files in one shot by
1226 separating them with commas, for example:
1228 echo enable,0xffff > /proc/acpi/ibm/hotkey
1229 echo lcd_disable,crt_enable > /proc/acpi/ibm/video
1231 Commands can also be specified when loading the thinkpad-acpi module,
1234 modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable
1236 Enabling debugging output
1237 -------------------------
1239 The module takes a debug paramater which can be used to selectively
1240 enable various classes of debugging output, for example:
1242 modprobe ibm_acpi debug=0xffff
1244 will enable all debugging output classes. It takes a bitmask, so
1245 to enable more than one output class, just add their values.
1247 Debug bitmask Description
1248 0x0001 Initialization and probing
1251 There is also a kernel build option to enable more debugging
1252 information, which may be necessary to debug driver problems.
1254 The level of debugging information output by the driver can be changed
1255 at runtime through sysfs, using the driver attribute debug_level. The
1256 attribute takes the same bitmask as the debug module parameter above.
1258 Force loading of module
1259 -----------------------
1261 If thinkpad-acpi refuses to detect your ThinkPad, you can try to specify
1262 the module parameter force_load=1. Regardless of whether this works or
1263 not, please contact ibm-acpi-devel@lists.sourceforge.net with a report.
1266 Sysfs interface changelog:
1268 0x000100: Initial sysfs support, as a single platform driver and
1270 0x000200: Hot key support for 32 hot keys, and radio slider switch
1272 0x010000: Hot keys are now handled by default over the input
1273 layer, the radio switch generates input event EV_RADIO,
1274 and the driver enables hot key handling by default in
1277 0x020000: ABI fix: added a separate hwmon platform device and
1278 driver, which must be located by name (thinkpad)
1279 and the hwmon class for libsensors4 (lm-sensors 3)
1280 compatibility. Moved all hwmon attributes to this
1281 new platform device.
1282 0x200100: Marker for thinkpad-acpi with NVRAM support. If you
1283 must, use it to know you should not start an userspace
1284 NVRAM poller (allows to detect when NVRAM is compiled
1285 out by the user because it is unneeded/undesired in